Verify cluster requirements

Before you create a replication policy, you must verify whether the cluster requirements are met.

The following table lists the features and the steps to complete before you create a replication policy in Replication Manager:


Feature/functionality	Verify whether the following steps are complete
To use source on-premises clusters	Is the source CDH cluster / source CDP Private Cloud cluster registered on the Management Console? For more information, see Add a CDH cluster and Adding a CDP Private Cloud Base cluster. important To register a CDP Private Cloud Base cluster as a classic cluster, use only the Cloudera Manager IP Address and Cloudera Manager Port options and not the Register KNOX endpoint (Optional) option.
To use AWS or ADLS as target clusters	Do you have valid cloud credentials to access and use AWS or ADLS as target clusters? For more information, see Working with Cloud Credentials. note When you add cloud credentials for your Amazon S3 account, you can choose one of the following authentication methods: Access secret key. To use this authentication type, you require an AWS Access Key and an AWS Secret key that you obtain from Amazon. Cloudera Manager stores these values securely and does not store them in world-readable locations. The credentials are masked and encrypted in the configurations passed to processes managed by Cloudera Manager, and redacted from the logs. IAM role. Amazon Identity and Access Management (IAM) can be used to create users, groups, and roles for use with Amazon Web Services, such as EC2 and Amazon S3. IAM role-based access provides the same level of access to all clients that use the role. You can choose the IAM role authentication type only when the following conditions are met: The source cluster is hosted on an AWS EC2 infrastructure. The source cluster Cloudera Manager and all the nodes in the cluster are running on an EC2 instance. The source cluster Cloudera Manager has the same IAM role. For information about configuring AWS credentials, see Introduction to role based provisioning credential in AWS.
To verify cluster access	Do you have the required access to create replication policies? Power users, the user who onboarded the source and target clusters, and users with ClassicClusterAdmin or ClassicClusterUser resource roles can create replication polices on clusters for which they have access. For more information, see Understanding account roles and resource roles. Do you have the required access to view the replication policies? HDFS replication policies - The existing policies are visible to users who have access to the source cluster in the policy. Hive and HBase replication policies - The existing policies are visible to Replication Manager users if they have access to the destination cluster in the policy. A warning appears if they do not have access to the source cluster. If you can view the policies, you can perform other actions on the policy which includes policy update and policy delete operations.
To replicate data securely	Have you configured an SSL/TLS certificate exchange between two Cloudera Manager instances that manage source and target clusters respectively? For more information, see Configuring SSL/TLS certificate exchange between two Cloudera Manager instances.
To create HDFS replication policies	Do the source cluster and target cluster meet the requirements specified in the Support Matrix? Is the source on-premises cluster registered as a classic cluster? Do you have the required cluster access to create or view replication policies? Do you have the required cloud credentials to access and use AWS or ADLS (target cluster)? Is an external account available in the Cloudera Manager instance that has access to the bucket or container where the HDFS data is being copied to? Have you configured an SSL/TLS certificate exchange between two Cloudera Manager instances that manage source and target clusters respectively to replicate data securely?
To create Hive replication policies	Do the source cluster and target cluster meet the requirements specified in the Support Matrix? Is the source on-premises cluster registered as a classic cluster? Do you have the required cloud credentials to access and use AWS or ADLS (target cluster)? Do you have the required cluster access to create or view replication policies? Is an external account configured on the source CDH cluster's Cloudera Manager that allows the CDH cluster to access CDP cloud storage? tip The external account can be configured on the Cloudera Manager > Administration page and the account has the access key / secret key pair that you can use to access CDP cloud storage. Have you configured an SSL/TLS certificate exchange between two Cloudera Manager instances that manage source and target clusters respectively to replicate data securely?
To create HBase replication policies	Do the source cluster and target cluster meet the requirements specified in the Support Matrix? Is the source on-premises cluster registered as a classic cluster? Are the following steps complete on the CDP Private Cloud Base source cluster or CDH source cluster (these steps are not required for COD sources)? Have you installed the HBase replication plugin parcel in the CDH source clusters? Applicable for CDH versions 7.2.x that are lower than 7.2.2, versions 7.1.x that are lower than 7.1.5, and for versions lower than 7.x. For more information, see Cloudera Replication Plugin. Have you created the /user/hbase folder for the hbase user in HDFS in the source cluster? Applicable for Cloudera Manager versions 7.4.3 or lower. tip To create the folder, run the following commands: `sudo -u hdfs hdfs dfs -mkdir /user/hbase sudo -u hdfs hdfs dfs -chown hbase:hbase /user/hbase` These commands allow the HBase replication policy to replicate the existing data in the source cluster. Do you have the required cloud credentials to access and use AWS or ADLS (target cluster)? Have you assigned the managed identity of source roles, Storage Blob Data Owner or Storage Blob Data Contributor, to the destination storage data container and vice versa for bidirectional replication when you are using COD on Microsoft Azure? The roles allow writing a snapshot in the destination cluster container. Do you have the required cluster access to create or view replication policies? Is the required target cluster (Data Hub or COD) available and healthy? For more information, see Data Hub and COD. Are the required ports including ports 2181 and 16020 on the destination hosts of the AWS cluster or ADLS cluster (target cluster), and the Cloudera Manager server port on the source cluster open and available? Verify whether the ports 16020 for worker security group and 2181 for worker, master, and leader groups are open for connection from the source cluster to the destination cluster on AWS or Azure. This ensures that the source HBase service can communicate with Zookeeper and HBase services on the destination hosts uninterruptedly. For more information, see Ports for HBase replication. Does DNS resolution work as expected between the source and destination clusters? tip If the destination cluster is not reachable from the source RegionServer hosts, add the hostname and IP address of the destination hosts to the /etc/hosts file on the RegionServers of the source cluster. Have you configured an SSL/TLS certificate exchange between two Cloudera Manager instances that manage source and target clusters respectively to replicate data securely?

You can also use CDP CLI commands for HDFS and Hive replication policies. The CDP CLI commands for Replication Manager are under the replicationmanager CDP CLI option. For more information, see CDP CLI for Replication Manager.